'identifier' : member function already defined or declared
This error could be caused by using the same formal parameter list in more than one definition or declaration of an overloaded function.
If you are compiling an ATL project, see Knowledge Base article Q241852.
The following sample generates C2535:
class C { public: void func(); // forward declaration void func() { // C2535, delete the forward declaration to resolve } }; void main() { }